<?php
/**
* This package contains four functions to be used for inserting
* or removing portions of a file mid-stream while reducing memory
* consumption by using a temp file instead for storing data in memory
*
* These functions are best when used with large files that cause
* memory capacity to be exceeded
*
* @author Sam Shull <sam.shull@jhspecialty.com>
* @version 1.0
*
* @copyright Copyright (c) 2009 Sam Shull <sam.shull@jhspeicalty.com>
* @license <http://www.opensource.org/licenses/mit-license.html>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*/
/**
* Insert a string into a file at the current position
* of the file pointer
*
* @param resource $fp
* @param string $str
* @param integer $length - maximum length to write to file
*
* @return integer
*/
function finsert ($fp, $str, $length=null)
{
$ret = 0;
$length = !is_null($length) ? (int)$length : strlen($str) + 1;
//flush all the written data
fflush($fp);
//track the current position
$current = ftell($fp);
//open a temp file for the rest of the data in the current file
$temp = tmpfile();
//copy the rest of the data in the file to a temp file
//stream_copy_to_stream($fp, $temp, -1, $current);
while (!feof($fp))
{
fwrite($temp, fread($fp, 4096));
}
//rewind the temp file
rewind($temp);
//rewind the file pointer to the current position
//using truncate allows the use of a+
ftruncate($fp, $current);
//write in the text
$ret += fwrite($fp, $str, $length);
//copy all the data back in
//stream_copy_to_stream($temp, $fp);
while (!feof($temp))
{
fwrite($fp, fread($temp, 4096));
}
//move the cursor to the end of the inserted text
fseek($fp, $current + $ret, SEEK_SET);
//get rid of the temp file
ftruncate($temp, 0);
fclose($temp);
//make sure to flush
fflush($fp);
return $ret;
}
/**
* Insert an array as a csv line into a file at the current position
* of the file pointer
*
* @param resource $fp
* @param array $fields
* @param string $delimiter = ,
* @param string $enclosure = "
* @param string $escape = \
*
* @return integer
*/
function finsertcsv ($fp, array $fields, $delimiter=",", $enclosure='"', $escape="\\")
{
$func = create_function('$a', '
$b=\''.str_replace("'", "\'", $enclosure).'\';
$c=\''.str_replace("'", "\'", $escape . ($escape == "\\" ? $escape : "")).'\';
return $b . str_replace($b, $c . $b, $a) . $b;
');
$str = implode(
$delimiter,
array_map(
$func,
$fields
)
);
return finsert($fp, $str . PHP_EOL);
}
/**
* Remove a portion of a file with a given length
* at the current position of the file pointer
*
* @param resource $fp
* @param integer $length
*
* @return boolean
*/
function fremove ($fp, $length)
{
$ret = false;
//flush all the written data
fflush($fp);
//track the current position
$current = ftell($fp);
//move the cursor to the desired position
fseek($fp, $length, SEEK_CUR);
//open a temp file for the rest of the data in the current file
$temp = tmpfile();
//copy the rest of the data in the file to a temp file
//stream_copy_to_stream($fp, $temp, -1, $current);
while (!feof($fp))
{
fwrite($temp, fread($fp, 4096));
}
//rewind the temp file
rewind($temp);
//rewind the file pointer to the current position
//using truncate allows the use of a+
$ret = ftruncate($fp, $current);
//copy all the data back in
//stream_copy_to_stream($temp, $fp);
while (!feof($temp))
{
fwrite($fp, fread($temp, 4096));
}
//move the cursor to the end of the inserted text
fseek($fp, $current, SEEK_SET);
//get rid of the temp file
ftruncate($temp, 0);
fclose($temp);
//make sure to flush
fflush($fp);
return $ret;
}
/**
* Remove a csv line from a file at the current position
* of the file pointer
*
* @param resource $fp
* @param array $fields
* @param string $delimiter = ,
* @param string $enclosure = "
*
* @return integer
*/
function fremovecsv ($fp, $length=0, $delimiter=",", $enclosure='"', $escape="\\")
{
$current = ftell($fp);
version_compare(PHP_VERSION, "5.3", ">=") ?
fgetcsv($fp, $length, $delimiter, $enclosure, $escape) :
fgetcsv($fp, $length, $delimiter, $enclosure);
$now = ftell($fp);
fseek($fp, $current, SEEK_SET);
return fremove($fp, $now - $current);
}
/**
* Insert a string at the beginning of a file
*
* @param resource $fp
* @param string $str
* @param integer $length - maximum length to write to file
*
* @return integer
*/
function fprepend ($fp, $str, $length=null)
{
$ret = 0;
$length = !is_null($length) ? (int)$length : strlen($str) + 1;
//flush all the written data
fflush($fp);
//track the current position
$current = ftell($fp);
rewind($fp);
//open a temp file for the rest of the data in the current file
$temp = tmpfile();
//copy the rest of the data in the file to a temp file
//stream_copy_to_stream($fp, $temp, -1, $current);
while (!feof($fp))
{
fwrite($temp, fread($fp, 4096));
}
//rewind the temp file
rewind($temp);
//rewind the file pointer to the current position
//using truncate allows the use of a+
ftruncate($fp, 0);
//write in the text
$ret += fwrite($fp, $str, $length);
//copy all the data back in
//stream_copy_to_stream($temp, $fp);
while (!feof($temp))
{
fwrite($fp, fread($temp, 4096));
}
//move the cursor to the end of the inserted text
fseek($fp, $current + $ret, SEEK_SET);
//get rid of the temp file
ftruncate($temp, 0);
fclose($temp);
//make sure to flush
fflush($fp);
return $ret;
}
/**
* Insert a string into a file at a specific distance from a given position
*
* @param resource $fp
* @param string $str
* @param integer $offset
* @param integer $length
* @param integer $whence = SEEK_SET
*
* @return integer
*/
function fchange ($fp, $str, $offset, $length, $whence=SEEK_SET)
{
$ret = 0;
//flush all the written data
fflush($fp);
fseek($fp, $offset, $whence);
fseek($fp, $length, SEEK_CUR);
//open a temp file for the rest of the data in the current file
$temp = tmpfile();
//copy the rest of the data in the file to a temp file
//stream_copy_to_stream($fp, $temp, -1, $current);
while (!feof($fp))
{
fwrite($temp, fread($fp, 4096));
}
//rewind the temp file
rewind($temp);
//rewind the file pointer to the current position
//using truncate allows the use of a+
ftruncate($fp, $offset);
//write in the text
$ret += fwrite($fp, $str, $length);
//copy all the data back in
//stream_copy_to_stream($temp, $fp);
while (!feof($temp))
{
fwrite($fp, fread($temp, 4096));
}
//move the cursor to the end of the inserted text
fseek($fp, $offset, $whence);
fseek($fp, $length, SEEK_CUR);
//get rid of the temp file
ftruncate($temp, 0);
fclose($temp);
//make sure to flush
fflush($fp);
return $ret;
}
/**
* Find an occurrence of a PCRE pattern in the next line from
* a given stream resource - used the same way fscanf would be used
*
* @param resource $fp
* @param string $regex
* @param array $matches = null
* @param integer $flags = 0
* @param integer $offset = 0
*
* @return integer
*/
function fpreg_match($fp, $regex, &$matches=null, $flags=0, $offset=0)
{
//if feof return 0 matches, else look for the pattern in the next line of the stream
return feof($fp) ? 0 : preg_match($regex, fgets($fp), $matches, $flags, $offset);
}
/**
* Find all of the occurrences of a PCRE pattern in a file
* from the given pointer position
*
* @param resource $fp
* @param string $regex
* @param array $matches = null
* @param integer $flags = 0
*
* @return integer
*/
function fpreg_match_all($fp, $regex, &$matches=null, $flags=0)
{
$pos = ftell($fp);
$matched = 0;
$match = null;
$matches = array();
$flag = $flags & PREG_OFFSET_CAPTURE;
while (!feof($fp))
{
if (preg_match($regex, fgets($fp), $match, $flag))
{
++$matched;
$matches[] = $match;
}
}
fseek($fp, $pos, SEEK_SET);
if ($matched)
{
if ($flags & PREG_SET_ORDER)
{
$ret = array();
$number = count($matches[0]);
foreach ($matches as $match)
{
for ($i=0;$i<$number;++$i)
{
if (!isset($ret[$i]))
{
$ret[$i] = array();
}
$ret[$i][] = isset($match[$i]) ? $match[$i] : null;
}
}
$matches = $ret;
}
}
return $matched;
}
?>
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